1. Field of the Invention
The present invention relates to a peeling machine for continuously cutting the outer peripheral surface of a round rod-like work, and in particular, to a feed mechanism for feeding the work to a cutter head.
2. Description of the Prior Art
Generally, a peeling machine includes a cutter head that rotates about a substantially horizontal mechanical center line to cut the outer peripheral surface of a round rod-like work, and a feed mechanism that holds the work on the mechanical center line between upper and lower feed rollers and feeds the work to the cutter head.
Japanese Unexamined Patent Publication No. H4 (1992)-226803 discloses various feed mechanisms for conventional peeling machines, and FIG. 8 shows one of the feed mechanisms. In FIG. 8, the feed mechanism includes a pair of upper and lower feed rollers 201, 202 that hold a round rod-like work W therebetween, and holders 203, 204 for supporting the feed rollers 201, 202, respectively, are supported by vertical respective guide rods 206, 206 so as to be vertically movable and to be driven by cylinders 210, 211, respectively. A synchronizing mechanism that moves the upper and lower holders 203, 204 in synchronization with each other is configured of a rocker lever 212, and a pair of connecting rods 220, 221 for connecting both ends of the rocker lever 212 to the upper and lower holders 203, 204.
With the configuration shown in FIG. 8, the synchronizing mechanism can change the position of the upper and lower feed rollers 201, 202 symmetrically in the vertical direction according to the works W having different diameters, thereby accurately holding the concerned work. Japanese Unexamined Patent Publication No. H4 (1992)-226803 also discloses a structure using a pair of upper and lower angle lever, as another example of the synchronizing mechanism.
In the feed mechanism shown in FIG. 8, the cylinders 210, 211 vertically move the holders 203, 204 for opening/closing the feed rollers 201, 202, and a grasping force to finally grasp the work W is derived from expansion/contraction of the cylinders 210, 211. That is, opening/closing of the upper and lower feed rollers 201, 202, positioning of the feed rollers 201, 202 with respect to the work, and grasping of the work with a predetermined pressure are all made by only controlling expansion/contraction of the cylinders 210, 211. However, with such configuration, it is difficult to rapidly open/close the feed rollers 201, 202, accurately position the feed rollers 201, 202, and grasp the work with an appropriate grasping force according to the diameter of the work. In other words, when the moving speed of the upper and lower holders is increased to improve the working efficiency, it becomes difficult to accurately position the feed rollers 201, 202, and suitably grasp the work with the appropriate grasping force according to the type of the work. Conversely, when the moving speed of the holders is decreased to enable grasping of the work with the appropriate grasping force according to the type of the work, working time increases, lowering the working efficiency.
When the grasping force with respect to the work is small, slippage between the work and the feed rollers occurs, inhibiting stable feeding. Conversely, when the grasping force with respect to the work is too large, for example, non-slip protrusions on the outer peripheral surfaces of the feed rollers may cause a transfer flaw on the surface of the work. Especially in cutting a soft material such as aluminum, the transfer flaw is likely to occur. Other feed mechanisms disclosed in Patent document 1 cause a similar problem.